#include <iostream>
using namespace std;
typedef long long LL;

LL a, b, p;

LL function()
{
	LL ret = 0;
	while(b)
	{
		if(b & 1) ret = (ret + a) % p;
		a = (a + a) % p;
		b >>= 1;
	}
	return ret;
}
int  main()
{
	cin >> a >> b >> p;
	cout << function() << endl;
	return 0;
}

